Luyten 726-8 (UV Ceti)

Luyten 726-8 (UV Ceti) is one of the nearest star systems to the Sun at a distance of 8.73 light-years
(see stars, nearest); it lies in the
constellation Cetus, northeast of Deneb
Kaitos (Beta Ceti). Luyten 726-8 is a binary in which both components
are red dwarfs in a highly elliptical orbit
of period 26.5 years that takes the two stars between 2.1 and 8.8 AU apart.
Component B is an extreme example of a flare
star that can surge in brightness by a factor of five in less than a
minute, then fall somewhat slower back down to normal luminosity within
two or three minutes before flaring suddenly again after several hours.
In 1952, Luyten 726-8 B, better known by its variable-star name UV Ceti,
was observed flaring to 75 times its normal brightness in only 20 seconds.
It is the prototype of the class known as UV
Ceti stars.